This specification relates to Internet search engines, and more particularly to providing information about groups of entities related to an entity identified by a search request.
A search system can provide one or more knowledge panels in response to a received search request. A knowledge panel is a user interface element that provides information related to a particular entity referenced by the search query. For example, the entity may be a person, place, country, landmark, animal, historical event, organization, business, sports team, sporting event, movie, song, album, game, work of art, concept, or any other entity.
In general, a knowledge panel provides information about the entity. For example, a knowledge panel for a famous singer may include the name of the singer, an image of the singer, a description of the singer, facts about the singer, content that identifies songs and albums recorded by the singer, and/or links to searches related to the singer. Other types of information and content can also be presented in the knowledge panel. Information presented in a knowledge panel can include content obtained from multiple disparate sources, e.g., multiple different web pages accessible over the Internet.
A search system can maintain an entity database that stores information about various entities. In some implementations, the system assigns a unique entity identifier to each entity. In some implementations, the entity database is curated. The system can assign one or more text string aliases to each entity. For example, the Statue of Liberty can be associated with aliases “the Statue of Liberty” and “Lady Liberty.” Aliases need not be unique among entities. For example, “jaguar” can be an alias for both an animal and a car manufacturer.
The system can also store information about an entity's relationship to other entities. For example, the system can define a “located in” relationship between two entities to reflect, for example, that the Statue of Liberty is located in New York City. In some implementations, the system stores relationships between entities in a representation of an entity graph in which entity nodes in the entity graph represent distinct entities and links between nodes represent relationships between the entities. In this example, the system can maintain an entity node representing the Statue of Liberty, an entity node representing New York City, and a link between the entity nodes to represent that the Statue of Liberty is located in New York City.